Chris Halstead, the 50-foot-wide Harkness Mansion and the super skinny 75 1/2 Bedford Street

At first glance, Manhattan’s toniest townhouses would seem to have little in common with mobile homes. But, in fact, both types of real estate share a metric for measuring value: the wider the better. Not only is townhouse width a point of pride for homeowners, buyers and brokers in New York City, it is one of the most important attributes appraisers use in determining the sale price of a townhouse, said Jonathan Miller, president of appraisal firm Miller Samuel. But how much does width actually impact the price per square foot of a property? [more]

452 Greenwich Street (Image c/o Trulia)

A Tribeca townhouse with a history of rapid appreciation is on the market again for $19.5 million, down from an initial asking price of $24.5 million, the New York Observer reported.

Owner Sean McCarthy has tapped Brown Harris Stevens superbroker Paula Del Nunzio to handle the sale. The four-story building at 452 Greenwich Street first sold for just under $500,000 in 1998, and then again in 1999 for $1.5 million. McCarthy purchased it in 2003 for $5.65 million, which means he would make a handsome return despite the markdown.  [more]

From left: Paula Del Nunzio and interior shots of the 625 Park listing

A co-op at the J.E.R. Carpenter-designed 625 Park Avenue — with the potential for a combination — has hit the market for $19.5 million, Curbed reported. Paula Del Nunzio of Brown Harris Stevens has the listing. [more]

From left: 311 West 11th Street and Annie Leibovitz

Famed photographer Annie Leibovitz has listed her West Village spread for $33 million, the Wall Street Journal reported. Paula Del Nunzio at Brown Harris Stevens has the listing.

The 10,200-square-foot home is comprised of three townhouses on a corner of Greenwich and West 11th streets. Leibovitz began assembling the property a decade ago. She purchased the first two buildings — 755-757 Greenwich Street — in 2002 for $4.2 million, then bought 311 West 11th Street a year later for $1.9 million, public records show. [more]

From left: the exterior and interior of 4 East 80th Street

The Woolworth mansion at 4 East 80th Street has hit the market for $90 million, Crain’s reported. Located between Fifth and Madison avenues, the property is currently the most expensive townhouse listed in the city, according to Streeteasy.com, and if sold, the sale would break the record for the largest price paid for a townhouse. [more]

Rothschild Mansion

After sitting on the market for nearly seven years and going through a litany of prices changes, the Upper East Side’s Rothschild Mansion will finally trade for $25 million to an unknown buyer, sources told Bloomberg News.

The Century Foundation, a think tank that analyzes U.S. public policy, had owned the six-story, 11,300-square- foot townhouse since 1958 and will now relocate to the Financial District, according to Derek Newton, a Century Foundation spokesperson. [more]

Paula Del Nunzio and the Woolworth mansion

Manhattan’s priciest residential townhouse listing can now be rented for $150,000 per month, the Observer reported. The famed Woolworth mansion, located at 4 East 80th Street in the Upper East Side, hit the market a year and a half ago, asking $90 million or $210,000 a month. The rental price was first trimmed in April of last year to $165,000. The rent slash comes as competition for other astronomically priced residences, such as 15 Central Park West and 50 Central Park South, both boasting $95 million listings, hit the market. [more]

From left: Vince Rocco, Andy Kim, 170 East 80th Street and the six-story waterfall

Amid plans to grow townhouse and new development divisions, the boutique brokerage Blu Realty Group has landed two high-priced townhouse listings — promising to use unconventional marketing strategies to sell the properties.

Andy Kim, the firm’s co-founder, will bring a $31 million Upper East Side townhouse to the market today, and Vince Rocco, a former Halstead Property broker who now heads Blu’s Riverside Boulevard office, will list a $17.5 million gutted townhouse next month. [more]

973 Fifth Avenue

A Fifth Avenue townhouse has closed for $42 million, the highest price paid for a New York City townhouse this year, according to the New York Observer. The 15,225-square-foot property, at 973 Fifth Avenue between East 78th and East 79th Streets, has been marketed since last June by Paula Del Nunzio of Brown Harris Stevens with a listing price of $49 million. [more]

From left: Paula Del Nunzio and 7 West 54th Street

An office building on West 54th Street is hitting the market at just less than $4,000 per square foot, the most expensive asking price ever for an office property, according to the Wall Street Journal. The building is a Beaux-Arts mansion at 7 West 54th Street, between Fifth and Sixth avenues, that was built more than a century ago as the home of Philip Lehman, the former head of Lehman Brothers. [more]